【摘要】 应用脉冲应答技术,研究了细直径管内纤维床层中的气体轴向扩散,使用的气体是N₂、H₂、He、Ar和空气。流速变化范围为0.01～20cm/sec。与小粒子床层一样,使用矩量法计算的轴向扩散系数也可以近似地用Burger型方程■来关联。对纤维床层,获得的扩散能力η=1.0,■散尺度ι=3.0mm。如果以U₀/D≈0.35mm^-1为界,用Burger型方程的两条直线来分别关联纤维床层中不同流速范围的轴向扩散系数时,其结果比用一个方程更接近于实验值。更多还原

【Abstract】 The axial dispersion coefficients of gas in a small diameter column packed with fibrous materials were determined by pulse response technique. N₂,He,H₂,Ar and air were used with linear velocity varied from 0.01 to 20 cm/sec.The experimental results indicated that axial dispersion of gas in fiber bed behaved in similar manner as in small granules bed to a certain extent.Therefore,axial dispersion coefficients of fiber bed calculated by the moment method could also be correlated approximately by Burger’s equation: E_A/D=η+l u₀/D where the diffusibility η=1.0 and the scale of dispersion l=3.0mm.If axial dispersion coefficients were estimated by using two straight lines derived from Burger’s equation,i.e.when u₀/D≤0.35mm^-1,E_A/D = 1.0 and u₀/D>0.35mm^-1,E_A/D=3.0u₀/D,the results gave better agreement with the observed values.更多还原